System for administering a restricted flight zone using radar and lasers

ABSTRACT

A system is disclosed for administering a restricted flight zone using radar and lasers for detecting, tracking, warning and destroying airborne craft that enter restricted flight zones without authorization or that approach dangerously close to protected areas on the ground. The system comprises a support for positioning adjacent the surface of the Earth at a bottom of the zone, detecting and defending apparatus mounted on the support for detecting airborne objects in the zone and defending against the airborne objects in the zone, and controlling apparatus for controlling the detecting and defending means.

REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.10/741,373, filed Dec. 19, 2003, now U.S. Pat. No. 6,906,659, issuedJun. 14, 2005.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to air defense systems, and moreparticularly pertains to a single unified system that may detect, warnand even destroy airborne objects that enter restricted flight zonesbefore the airborne objects can strike buildings, facilities or personson the ground.

2. Description of the Prior Art

Restricted flight zones, including the so-called “no fly” zones, areoften defined in terms of a geographical zone on the Earth's surface.The administration of the air space in the restricted flight zonestypically requires monitoring the identity, movement, and activity ofvarious airborne objects in the air space of the zone.

Radar systems using radio frequency waves are well known for detectingand tracking objects in the atmosphere of the Earth for the purpose ofair defense. Such systems use transmitters to transmit radio waves intoa selected area of the atmosphere and receivers to detect any radiowaves that bounce back from a detected object within the area oftransmission. Radar is used for guiding manned aircraft and unmannedweapons systems to their targets for interception, and, if necessary,for destruction. Thus, the conventional air defense systems havetypically employed one system for detecting and tracking objects in theatmosphere, and a relatively separate system for destroying, orotherwise rendering ineffective, objects representing a threat to theprotected ground area below the area of the atmosphere being patrolled.

Phased array radar, in which the frequency and amplitude are in phase,is a system that uses a stationary radar antenna that can transmit inone direction. The same antenna both transmits and receives radar wavesignals. The degree of angle for coverage of the phased array radar canbe set by the control subsystem of the radar. One precision approachradar, for example, covers 30 degrees of the horizon. Each system can beset to transmit and receive radar signals on a different frequency. Suchsystems are currently used by the U.S. Navy for precision approach radaron aircraft carriers, at airports, and to track missiles.

Lasers (which is an acronym for Light Amplification by the StimulatedEmission of Radiation) have been developed that employ relatively higherfrequency, shorter wavelength electromagnetic radiation waves in theultraviolet, visible and infrared region of the electromagneticspectrum. A laser is an electro-optical device for producing a highpower, monochromatic, low divergence, and coherent light source.

Different types of lasers can be employed for a transmitter, dependingupon the power and wavelength of the electromagnetic wave employed inthe laser system. The portion of the laser generating device where theexcitation of the atoms actually occurs may be in a medium thatcomprises a solid, liquid, or gaseous material.

Solid state laser emissions are produced, for example, when high-voltageelectricity causes a quartz flash tube to emit an intense burst oflight, exciting some of the atoms in a ruby crystal to higher energylevels. At a specific energy level, some atoms emit particles of lightcalled photons. At first, the photons are emitted in all directions.Photons from one atom stimulate emission of photons from other atoms andthe light intensity is rapidly amplified. Mirrors at each end reflectthe photons back and forth in the medium, continuing this process ofstimulated emission and amplification. The photons leave through thepartially silvered mirror at one end, and these exiting photons form thelaser light emission or beam. By varying the intensity of the lightsource, the intensity of the laser output also can be varied.

Some of the military applications of lasers involve shooting downmissiles. An example of this application occurred during a Jun. 7, 2000test at White Sands Missile Range, N.M., in which the U.S. Army used itsTactical High Energy Laser/Advanced Concept Technology Demonstrator(THEL/ACTD) to shoot down a rocket carrying a live warhead. The testdemonstrated the first high-energy laser weapon system designed foroperational use. After the rocket was launched, a fire control radardetected the rocket, tracked it with its high precision pointer trackersystem, and then engaged the rocket with its high-energy chemical laser.After several seconds of having the laser beam directed on the warhead,the rocket exploded in mid-air.

The U.S. Army and Air Force also have been testing a similar airbornesystem using solid state lasers. The lasers may be carried by airplanesthat may direct the beams at incoming missiles to destroy them, similarto the Jun. 7, 2000 test at White Sands Missile Range.

One system developed by the Raytheon Co. includes a portable tacticalhigh energy solid state laser that may be deployed on top of Humveepersonnel transport vehicles or tanks and that may generate 100kilowatts of energy to be aimed at a specific target. Intended targetsinclude aircraft, such as helicopters and airplanes. Furtherdevelopments will attempt to increase the intensity of solid statelasers, possibly to shoot down missiles at greater distances.

The present invention substantially departs from the conventionalconcepts and designs of the prior art, and in so doing provides anapparatus primarily developed for the purpose of providing a singleunified system that may detect, track, warn and even destroy airborneobjects that enter restricted flight zones without authorization, oreven approach so closely to protected areas on the ground that theprotected areas are in danger of damage or destruction by collision fromthe airborne craft.

SUMMARY OF THE INVENTION

In view of the foregoing limited uses of lasers and radar present in theknown prior art, the present invention provides a new apparatus andmethod for detecting, tracking, warning and destroying airborne craftthat enter restricted flight zones without authorization or thatapproach dangerously close to protected areas on the ground.

The general purpose of the present invention, which will be describedsubsequently in greater detail, is to diminish the risk of military,terrorist, or even accidental attacks that could be accomplished throughaircraft or other airborne objects striking an object, area or personson the ground.

To attain this, the present invention generally comprises a support forpositioning adjacent the surface of the Earth at a bottom of the zone,detecting and defending means mounted on the support for detectingairborne objects in the zone and defending against the airborne objectsin the zone, and controlling means for controlling the detecting anddefending means.

In one preferred embodiment of the invention, the detecting anddefending means comprises a plurality of radar/laser clusters mounted onthe support, and each of the radar/laser clusters transmit along an axisdefining a detection vector. The axis of the detection vector of eachradar/laser cluster radiates outwardly from the support and extendinginto and through the zone.

In one preferred embodiment of the invention, each of the radar/laserclusters comprises at least one radar assembly for detecting airborneobjects in the zone, and at least one laser assembly for defendingagainst airborne objects in the zone. The laser assembly generates alaser beam extending along an axis of a defending vector.

The system may be programmed to detect airborne objects via the radarassemblies of one or more clusters, and illuminate the laser assembliesof those clusters upon the detection of an airborne object within therestricted flight zone. As airborne objects enter a restricted flightzone, the system may illuminate the laser assemblies of the clusterswhose radar assemblies have detected reflected radio waves indicatingthe presence of the airborne object. The laser assemblies may have avariable intensity, and as the airborne object approaches closer to thesupport in the protected zone, the intensity of the laser beams from thelaser assemblies may be increased. Initially, as the airborne objectsenter the restricted flight zone, the laser beams may be of a relativelylow intensity so as to serve merely to warn the airborne object orobjects (and their pilots) of their trespass into the restricted flightzone. As the airborne object continues moving further into therestricted flight zone, the system may increase the power to the laserassemblies to thereby gradually increase the intensity of their laserbeams. Before the airborne objects could strike the system, or objects,persons or facilities on the ground, the intensity of the lasers wouldincrease to a relatively high intensity, thereby most likely destroyingthe airborne object in mid-air by burning through its operational flyingcomponents, its fuel tank, or its fuselage.

Airborne objects moving beyond the defending vector of one radar/lasercluster and into the defending vector a second cluster may be tracked bythe second cluster which would continue the defensive laser illuminationat the same intensity as the first cluster. The intensity may bedetermined by proximity to the support or protected objects, azimuth,and speed of the airborne object, rather than, for example, length oftime within the restricted flight zone.

For airborne objects approaching at relatively faster speeds, theintensity of the lasers may increase to relatively higher levels at agreater distance from the system than those airborne objects moving atslower speeds, and thus the slower airborne objects may be hit by thehigher intensity laser beams only when they have moved closer to thesystem of the restricted flight zone. Because the fastest airborneobjects represent the greatest threat of striking the protected area,the purpose of varying the intensity of the laser beams would be todeflect or destroy approaching airborne objects based on the immediacyof the threat created by their speed and angle of approach.

Optionally, airborne objects authorized to enter the restricted flightzone may be equipped to send a coded radio signal to a receiver of thesystem to deactivate the defensive mechanism of the system with respectto that airborne object.

There has thus been outlined, rather broadly, the more importantfeatures of the invention in order that the detailed description thereofthat follows may be better understood, and in order that the presentcontribution to the art may be better appreciated. There are additionalfeatures of the invention that will be described hereinafter and whichwill form the subject matter of the claims appended hereto.

In this respect, before explaining at least one embodiment of theinvention in detail, it is to be understood that the invention is notlimited in its application to the details of construction and to thearrangements of the components set forth in the following description orillustrated in the drawings. The invention is capable of otherembodiments and of being practiced and carried out in various ways.Also, it is to be understood that the phraseology and terminologyemployed herein are for the purpose of description and should not beregarded as limiting.

As such, those skilled in the art will appreciate that the conception,upon which this disclosure is based, may readily be utilized as a basisfor the designing of other structures, methods and systems for carryingout the several purposes of the present invention. It is important,therefore, that the claims be regarded as including such equivalentconstructions insofar as they do not depart from the spirit and scope ofthe present invention.

Advantages of the invention, along with the various features of noveltywhich characterize the invention, are pointed out with particularity inthe claims annexed to and forming a part of this disclosure. For abetter understanding of the invention, its operating advantages and thespecific objects attained by its uses, reference should be made to theaccompanying drawings and descriptive matter in which there areillustrated preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood and objects of the inventionwill become apparent when consideration is given to the followingdetailed description thereof. Such description makes reference to theannexed drawings wherein:

FIG. 1 is a schematic side view of a new system according to the presentinvention with the laser emissions being represented by lines radiatingoutwardly from a support of the system.

FIG. 2 is a schematic side view of the support of the present inventionwith a portion of the outer extent of the support broken away at one ofthe ports in the support to show a radar/laser cluster comprising aradar assembly antenna and a set of laser assemblies.

FIG. 3 is a schematic depiction of an airborne object moving into thezone protected by the system employed on a ship, and radio transmissionsby the authorized airborne objects to the system to alter operation ofthe system with respect to those authorized airborne objects.

FIG. 4 is a schematic diagram of a radar assembly of a radar/lasercluster.

FIG. 5 is a schematic diagram of the relationship between oneradar/laser cluster and the controlling means, and the relationship ofthe identification means to the components of the controlling means.

FIG. 6 is a schematic diagrammatic representation of one configurationof a radar/laser cluster of the system of the invention.

FIG. 7 is a schematic diagrammatic representation of anotherconfiguration of a radar/laser cluster of the system of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

With reference now to the drawings, and in particular to FIGS. 1 through7 thereof, a new system for administering a restricted flight zone usingradar and lasers embodying the principles and concepts of the presentinvention and generally designated by the reference numeral 10 will bedescribed.

The invention contemplates a system 10 that creates a hemispherical zone12 about a location on, or slightly above, the surface 2 of the Earth,whether comprising land 3 or a body 4 of water or a combination of both(see FIG. 1). In this zone 12 created by the system of the invention,objects such as, and most importantly, aircraft 5 and missiles 6 may bedetected, tracked and optionally destroyed by the system for protectingthe area 14 about the location of the system 10 in the zone 12. For thepurposes of the following description, the protected zone 12 refers tothe generally hemispherical space extending above the surface of theEarth and generally centered on the location at which the system isoperating. The protected area 14 referred to describes the generallycircular part of the surface of the Earth that lies below the protectedzone and is generally centered on the location of the system.

The system 10 includes a support 20 that is preferably positioned at alocation substantially central to the area 14 to be protected (see FIG.1), and may be located at the horizontal center of the zone 12. In oneembodiment of the invention, the support 20 has a convex outer extent 22(see FIGS. 1 and 2). The convex outer extent 22 is most preferablyhemispherical in shape, although relatively flatter or less curvedconvex outer extent shapes may be used. In a preferred embodiment of theinvention, the outer extent of the support comprises a generallycontinuous outer surface 24, and may thus comprise a hemispherical domestructure. Optionally, the support may be fixed in position, or could bemade relatively mobile for moving between locations. Ideally, thestructure of the support is formed from a relatively strong,heat-resistant material, such as a carbon composite material or adurable ceramic material. As a further option, substantially the entirestructure (including the laser and radar-transmitters described below)could be enveloped in a rugged armoring material to protect the systemfrom damage, and the armoring material may form the outer extent of thesupport. Portals may be formed in the protecting material to allow freepassage of laser beams and radar waves outwardly from the support, butthe portals should not be so small that the outer extent impedesreception of radar waves returning to the radar antenna after bouncingoff of aircraft or other airborne objects moving through the restrictedflight zone.

The interior of the structure of the support 20 may be substantiallyopen or hollow to accommodate the laser transmitters and phased arrayradar antennae (see FIG. 2). Other components of the laser and radarsystem of the invention optionally may be located outside of thestructure of the support to protect the components from heat andradiation generated by the laser transmitters, as well as permittingeasier maintenance and replacement of the components.

The system 10 includes detecting and defending means mounted on thesupport 12 for detecting airborne objects in the zone and defendingagainst the airborne objects in the zone. In one embodiment of theinvention, the detecting and defending means comprises a plurality ofradar/laser clusters 26 for detecting and monitoring airborne objects inthe zone 12 (see FIGS. 2 and 6). The plurality of radar/laser clusters26 may be mounted on the support 20. Each of the radar/laser clusters 26may transmit along an axis 27 that defines a detection vector extendingfrom the radar/laser cluster into and through the zone 12. The axis 27of the detection vectors of the plurality of the radar/laser clusters 26may radiate outwardly from the support with substantially uniform anglesbetween the axes of the adjacent radar/laser clusters.

Each of the radar/laser clusters 26 includes at least one radar assembly28 and at least one laser assembly 30. Each of the radar assemblies 28may comprise a radar transmitter 32, a radar receiver 34, and an antenna36. The antenna 36 is in communication with the radar transmitter 32 andradar receiver 34 (see FIG. 4). The antenna 36 of the radar transmitter32 transmits along the axis 27 of the detection vector, and the antennais also adapted to receive return waves reflected from an airborneobject along the axis of detection vector (see FIG. 2). The laserassembly 30 may comprise a laser transmitter 38 that generates a laserbeam 39 which may be oriented along an axis 29 of a defending vector.Preferably, the axis 29 of the detection vector is orientedsubstantially parallel to the axis 27 of the defending vector of theradar/laser cluster.

The radar/laser clusters 26 may each have an outer limit of effectiverange that defines an outer periphery of the zone or the furthest extentof the zone, with the radial reach of the plurality of radar/laserclusters defining an outer periphery of the substantially hemisphericalzone.

Each of the plurality of radar/laser clusters 26 may include a set 40 ofmore than one laser assembly 30 (see FIG. 6), and the set of lasertransmitters 38 of the more than one laser assemblies of eachradar/laser cluster may be oriented such that the axis 29 of thedefending vector of each laser transmitter 38 of the set 40 issubstantially parallel to the axis of the defending vector of otherlaser transmitters 38 of the set. The laser transmitters 38 of the laserassembly 30 of each radar/laser cluster may be positioned around theantenna 36 of the radar assembly 28 of the radar/laser cluster.Illustratively, as shown in FIG. 6, the radar/laser cluster 26 may havethe laser transmitters 38 of the set oriented about the radar antenna36. Preferably, all of the laser transmitters 38 in each set 40 of laserassemblies transmit the laser beams simultaneously, or substantiallysimultaneously, into the zone. Optionally, as shown in FIG. 7, the lasertransmitters 38 may be positioned in a line about the radar antenna 36.

The plurality of radar/laser clusters 26 may be positioned in an arraythat substantially covers the outer extent 22 of the support 20 (seeFIGS. 1 and 2). Preferably, the radar/laser clusters are arrayed closelyenough together along the outer extent of the support that nosignificant gaps exist in the laser beams radiating outwardly from thesupport that might allow an unauthorized airborne object to move throughthe protected zone 12 while avoiding being hit by one or more laserbeams. The actual number of radar/laser clusters mounted on the supportmay vary. It is believed that using less than approximately 100 lasertransmitters would in many cases provide inadequate protection for asubstantially hemispherically-shaped halo 44. The greater the number oflaser transmitters that can be arrayed on the dome, and the more tightlythe laser beams are grouped and the closer the laser beams of adjacentradar/laser clusters may be positioned, the relatively better theprotection that may be provided by the radar/laser clusters againstairborne objects moving into the protected zone 12.

The outer extent 22 of the support 20 may comprise a substantiallycontinuous surface, and a plurality of ports 25 may be formed in thesurface for permitting the laser beam 39 from the laser assembly 30 andthe radar signals of the radar assembly 28 of the same radar/lasercluster 26 to pass through the same port 25 such that radar signals mayboth be transmitted and received by the antenna of the radar assemblythrough the same port 25 which the laser beam passes through.Preferably, the array of radar/laser clusters 26 is substantiallycoextensive with the outer extent 22 of the support 20 and are arrangedin a substantially uniform density covering the outer extent forcreating a halo 44 of radar waves and laser beams about the support 20and in the zone 12 (see FIG. 1). In one embodiment of the invention, theplurality of radar/laser clusters are positioned in a plurality of rowsthat extend from a top center of the outer extent 22 of the support 20downwardly toward the periphery of the support, although more randomlypositioned configurations of the radar/laser clusters may be employed.

The axis 29 of the defending vector of each of the radar/laser clusters26 may be oriented at an angle with respect to a normal axis that isoriented substantially perpendicular to a plane oriented tangent to theouter surface 24 of the outer extent of the support 20 (see FIG. 2). Theaxis 29 of the defending vector of each of the laser transmitters 38 ofthe set 40 for a radar/laser cluster may be oriented at substantiallythe same angle with respect to the normal axis, and preferably theangles formed by the axis of the defending vector and the normal axishave a non-zero measurement. However, the laser beam 39 of each lasertransmitter 38 preferably does not cross the axes of other laser beamsof other laser transmitters of other radar/laser clusters. In oneillustrative embodiment, the path of the seams of a set 40 of lasertransmitters 38 are oriented parallel to the normal axis of thehemispherical outer surface while the phased array radar of the same set40 is also oriented parallel to the normal axis of the outer surface(see FIG. 2).

The radar assembly 28 of each radar/laser cluster 26 may transmit andreceive radar signals at a frequency that is different from thefrequencies at which the radar assemblies of the other radar/laserclusters transmit and receive for facilitating the determination of theposition of an airborne object in the zone.

The laser transmitters 38 may be capable of generating laser beams ofvariable intensity, and a range of the intensities of the laser beams ofthe laser transmitters may extend from a relatively low intensity to arelatively high intensity. The relatively low intensity may besubstantially harmless to airborne objects (such as a beam that merelyilluminates the objects that the laser beam strikes) and the relativelyhigh intensity may be capable of generating heat in an airborne object,and may raise the temperature of portions of the airborne object to suchan extent that any explosive material contained in the airborne objectis ignited by the heat. Thus, the intensity of the laser beams generatedby the laser transmitters may have sufficient energy to destroy objectsstruck by the laser beam within a predetermined distance from the lasertransmitter in the zone. Illustratively, the laser transmitters maygenerate laser beams having intensities greater than approximately 100kilowatts.

The invention may also include controlling means for controlling theradar assemblies 28 and the laser assemblies 30 of each of theradar/laser clusters 26, and for controlling and coordinating the radarsand lasers, and may comprise a programmable computer. The programmablecomputer of the system of the invention would provide information suchas the distance to the targeted object, the speed of the targetedobject, the azimuth, or angle of trajectory, of the targeted objectsand, optionally, the size and shape of the targeted objects, dependingon the sensitivity of the radar system selected.

The controlling means 50 may comprise processing means, such as aprocessor 52 of the programmable computer, for processing informationreceived from the antennas 36 of the radar assemblies 28 and the lasertransmitters, and may also comprise storage means, such as memory 54,for storing information gathered by the processor (see FIG. 5). Theprocessing means may process information from the radar assemblies ofthe clusters signals for comparing the information from the differentradars such that airborne objects may be detected and tracked as theobjects reflect radar waves back toward the radar antennae. Thecontrolling means of the system may also include a signal processor, acombiner to interface with and combine radar information from radarassemblies of co-located radar/laser clusters, a multiplexer, groundnetworking, real-time monitoring and assessment capabilities, definablealarm limits to determine the degree to which the intensity of thelasers should increase as unauthorized airborne objects encroach, systemsupport pedestals, a power supply, a computer local area network, dataprocessors, an executive monitor, recorders, data acquisition and systemcontrol circuitry. Programming similar to that developed for phasedarray radar air traffic control systems could be used, but the systemwould need to be adapted to coordinate inputs from multiple radars andlasers emitting in sequence.

The controlling means may also comprise identification means, such as anidentification circuit 56, for identifying authorized airborne objectsin the zone 12. The identification circuit may comprise a radio receiver60 for receiving radio signals from an authorized airborne object, andthe controlling means (such as the processor 52) may be adapted tomodify operation of the radar/laser clusters 26 with respect to theauthorized airborne object when the radio signals are received from theauthorized airborne object in the zone 12 until the authorized airborneobject leaves the zone. For example, the processor 52 may suppress thetransmission of laser beams 39 into the zone 12 while the authorizedairborne object is present, or may at least suppress laser beamtransmission in the direction of the authorized airborne object until itmoves out of the zone. Conversely, the intensity of the laser beams 39generated by the laser transmitters 38 may be controlled by thecontrolling means in such a manner so that the intensity of the laserbeams of the laser transmitters are increased as an unauthorizedairborne object moves closer to the support 20.

In greater detail, two kinds of lasers may be used within the samesystem. Solid state lasers, because of their size and relative ease ofuse, would be the preferred system with the status of currenttechnologies. Solid state lasers may use ruby crystals to condense anddirect light into beams. Chemical lasers, which can be the highestintensity and cause the greatest damage to objects struck by its beam,may also be used in the invention, especially if technologies improve tomake them smaller and more practical. Chemical-based lasers typicallyemploy a gaseous material, such as carbon dioxide (CO2), to create thelaser beam. In either case, the lasers should comprise laser beams thatare continuously projected, rather than being intermittently pulsedbeams.

In operation, each set of the laser transmitters 38 may preferably bedirected by the controlling means to fire in sequence with thecoextensive field of radar waves created by each phased array radartransmitter 32 as an unauthorized airborne object enters the zone andthe field of radar waves. With the aid of the radar assembly for eachset of lasers assemblies of a cluster 26, high-energy lasers can depositintense amounts of infrared energy on targets at distances of tens ofmiles, or more. The intense energy and the speed of lightcharacteristics make lasers attractive for defending against aircraft,missiles and short-range rockets among other threatening airborneobjects.

When the radar assembly of one or more of the radar/laser clusters firstdetects an airborne object within or approaching too close to arestricted flight zone, information from the radar receiver 34 of theradar/laser clusters may be transmitted to processor 52 of thecontrolling means. The software of the processor may then turn on thelaser transmitters 38 of the set 40 corresponding to the radar assemblyof the detecting radar/laser cluster. Initially, at the farthestperimeter of the zone, the laser transmitters may be at their lowestpower setting of intensity, which could be as low as approximately 5watts. As the airborne object moves further into or across the zone, theprocessor may signal the laser transmitters to increase the powersetting of intensity proportionate to the proximity to the support, orthe perceived danger presented by the airborne object to protectedareas, objects, persons, or facilities.

The danger presented by the airborne object may quantified, and thusmeasured, by the processor 52 as a combination of the speed of theairborne object, the angle of approach of the airborne object withrespect to the support or the protected objects, persons, or facilities,and the proximity of the airborne object to the protected objects,persons or facilities. A highest intensity of the laser transmitterscould range up to 100 kilowatts or more, depending on the limits of thelaser assemblies. A system administrator may decide the rate at whichthe intensity of the laser beams should increase and set thetransmitters accordingly.

Illustratively, an airplane approaching on a direct collision coursewith a protected object, person or facility at a speed of approximately500 miles per hour may be hit by the highest intensity of laser beam ata distance of approximately five miles from the projected point ofcollision. In another illustration, an airplane crossing into the no-flyzone at approximately 150 miles per hour on a course that leads awayfrom the zone may be hit with a relatively low intensity laser beam asclose as approximately two miles from the protected objects, persons orfacilities, so that little or no damage is caused to the aircraft.Instead, the lower intensity laser beams would serve to warn the pilotof the aircraft of the encroachment.

The system may intensify the laser beam or beams to a potentiallydestructive and deadly intensity level only at the point that anencroaching airborne object represents a significant threat of death ordestruction to protected objects, persons or facilities on the ground.The purpose of increasing the intensity of the laser beams tohigh-intensity levels would be to destroy the encroaching airborneobject in mid-air, before it has an opportunity to hit objects, personsor facilities on the ground.

High-intensity, or high-energy, is a relative term, and depends upon theamount of energy used for comparable systems. Moreover, improvements intechnology often increase the intensity available from different kindsof lasers, thereby making some lasers relatively high intensity whenpreviously they were considered relatively lower intensity.

The high-intensity, or high-energy, lasers should be used in the lasertransmitters of the invention only to the extent they can be operatedwithout damaging other systems of the invention, such as, for example,burning out electrical wiring. Also, the high-energy lasers may beemployed as long as undue risks to safety, health or the environment ofthe protected area are not created. The intensity of the lasers shouldbe set to adequately protect the restricted flight zone without causingundue dangers to persons or facilities on the ground or the systemitself. When the system is deployed, it is contemplated that the powerof the laser transmitters may be adjusted to levels where theundesirable effects are minimized to a tolerable level. Optionally, thepower level of the laser transmitters may be adjusted or varied duringoperation of the system based on environmental factors.

In greater detail, the antennas of the radar assemblies may comprisemonostatic antennae that function both to transmit the radar waves at acertain frequency and to receive the rebounding or reflected radar wavesof the same frequency. Each of the radar receivers may be set to receiveradar signals at a specific frequency unique to that specific radartransmitter/receiver antenna, thereby ensuring the laser assembly orassemblies of the radar/laser cluster would transmit outwardly only whenan intruding aircraft has entered the portion of the zone 12 monitoredby the corresponding radar assembly of the cluster.

To minimize signal noise from other radar or radio sources that couldcause a mistaken firing of lasers of any of the surrounding sets, eachradar assembly may be programmed to detect only radar waves at aspecific frequency, which should be the same frequency at which the sameradar assembly transmitted its signal. Each radar assembly on thesupport may operate at different frequencies to help ensure that eachradar assembly detects only the radar waves emitted by that radarassembly.

The fields of outwardly-directed laser beams created by each laserassembly may be separated in orientation so that they no more thanminimally overlap with the fields created by all surrounding laserassemblies of adjacent radar/laser clusters. As trespassing, orencroaching, airborne objects fly into the field of each radar/lasercluster, the laser transmitter or transmitters of a particular set wouldfire. As the aircraft passed beyond the field of one radar/laser clusterand into the field of another radar/laser cluster, the set of lasertransmitters for the first radar/laser cluster would cease firing.However, the set of laser transmitters of the second radar/laser clustermay begin firing, with an intensity determined by the danger presentedby the airborne object, based on its proximity, speed and azimuth, ortrajectory, characteristics.

In one embodiment of the invention, the support of the system may beplaced on a raised platform, or tower, located in the midst of a sitewhere protection is desired, such as on a government building, a nuclearpower plant, a chemical plant, a hydroelectric dam, a bridge, askyscraper or a military installation, to create a canopy over the area.

Optionally, in another embodiment of the invention, the system, or aplurality of the systems, could be located on relatively higher terrainfeatures, such as hillsides or mountaintops, that are located nearcities, military bases or other sites to be protected. Because theperiphery of the system may extend tens of miles or more, depending onthe power of the radar and laser transmitters, relatively expansiveareas such as large cities or other sites may be protected.

Optionally, in yet another embodiment of the invention, the system couldbe positioned on a ship or barge on a body of water, such as off thecoast of areas that need to be protected (see FIG. 3). Rather than usinga system of the invention with a substantially hemispherical periphery,the system may be modified to cover a fraction of a hemispherical space,such as half of the hemispherical space, and it will be realized thatthis may be accomplished by “turning off” a portion of the radar/laserclusters on the support. Such partial protection may be employed, forexample, adjacent to a coastal area.

With respect to the above description then, it is to be realized thatthe optimum dimensional relationships for the parts of the invention, toinclude variations in size, materials, shape, form, function and mannerof operation, assembly and use, are deemed readily apparent and obviousto one skilled in the art, and all equivalent relationships to thoseillustrated in the drawings and described in the specification areintended to be encompassed by the present invention.

Therefore, the foregoing is considered as illustrative only of theprinciples of the invention. Further, since numerous modifications andchanges will readily occur to those skilled in the art, it is notdesired to limit the invention to the exact construction and operationshown and described, and accordingly, all suitable modifications andequivalents may be resorted to, falling within the scope of theinvention.

1. A system for detecting airborne objects in a zone occupying athree-dimensional space in the atmosphere above the Earth and forsimultaneously defending against the airborne objects located in thezone, comprising: a support for positioning adjacent the surface of theEarth at a bottom of the zone; a detecting and defending means mountedon the support for detecting airborne objects in the zone and defendingagainst the airborne objects in the zone; and controlling means forcontrolling the detecting and defending means; wherein the detecting anddefending means comprises a plurality of clusters mounted on thesupport, each of the clusters comprising: at least one radar assemblyfor detecting airborne objects in the zone; and at least one laserassembly for defending against airborne objects in the zone.
 2. Thesystem of claim 1 wherein each of the clusters transmits along an axisdefining a detection vector, the axis of the detection vector of eachcluster radiating outwardly from the support and extending into andthrough the zone.
 3. The system of claim 1 wherein the laser assemblygenerates a laser beam extending along an axis of a defending vector. 4.The system of claim 3 wherein each of the plurality of clusters includesa set of more than one laser assembly, the set of laser transmitters ofeach cluster being oriented such that the axis of the defending vectorof each laser transmitter of the set is substantially parallel to theaxis of the defending vector of other laser transmitters of the set. 5.The system of claim 4 wherein the support has an outer extent with asubstantially convex outer surface; and wherein the axis of thedefending vector of each of the laser transmitters of the clusters isoriented at an angle with respect to a normal axis, the normal axisbeing oriented substantially perpendicular to a plane oriented tangentto the outer surface of the outer extent of the support, the axis of thedefending vector of each of the laser transmitters of the set of a saidcluster being oriented at substantially the same angle with respect tothe normal axis.
 6. The system of claim 3 wherein a portion of theplurality of lasers directed along an axis of a defending vector againstencroaching aircraft are configured to transmit lasers of differentcolors within the plurality of lasers for warning pilots of theirtrespass into a flight restricted zone.
 7. The system of claim 1 whereinthe radar assembly comprises a radar transmitter, a radar receiver, andan antenna in communication with the radar transmitter and radarreceiver; and the laser assembly comprises a laser transmitter.
 8. Thesystem of claim 7 wherein the laser transmitters of the laser assemblyof each cluster are positioned around the antenna of the radar assemblyof the cluster.
 9. The system of claim 1 wherein the plurality ofclusters each have an outer limit of effective range that defines anouter periphery of the zone, the outer periphery of the zone beingsubstantially hemispherical.
 10. The system of claim 1 wherein thecontrolling means controls the radar assemblies and the laser assembliesof the clusters, the controlling means comprising processing means forprocessing information from the radar transmitters and radar receivers.11. The system of claim 1 wherein the controlling means comprisesidentification, means for identifying authorized airborne objects in thezone, the identification means comprising a radio receiver for receivingradio signals from an authorized airborne object, the controlling meansbeing configured to modify operation of the clusters with respect to theauthorized airborne object when the radio signals are received from theauthorized airborne object until the authorized airborne object leavesthe zone.
 12. The system of claim 1 wherein the support has an outerextent with a substantially convex outer surface; and wherein theplurality of clusters are positioned in an array substantially coveringthe outer extent of the support.
 13. The system of claim 1 wherein theradar assembly of each cluster transmits and receives radar signals at afrequency that is different from frequencies at which the radar assemblyof each of the other clusters transmit and receive.
 14. The system ofclaim 1 wherein the laser transmitters of the laser assemblies of theclusters are configured to selectively generate laser beams of variableintensity.
 15. The system of claim 14 wherein the intensity of the laserbeams generated by the laser transmitters is sufficient to destroyobjects struck by the laser beam within a predetermined distance fromthe laser transmitter in the zone.
 16. The system of claim 14 whereinthe intensity of the laser beams generated by the laser transmitters iscontrolled by the controlling means, the controlling means increasingthe intensity of the laser beams of the laser transmitters as anairborne object moves closer to the support.
 17. The system of claim 16wherein the controlling means of the system is configured to beselectively overridden by manual operation to control the intensity ofthe lasers and the direction of the lasers.
 18. The system of claim 1wherein the laser assembly of the cluster emits a laser beam only whenan airborne object is detected entering the zone.
 19. The system ofclaim 1 wherein the laser transmitters of the laser assemblies of theclusters could be set to generate laser beams of only one intensity. 20.A system for detecting airborne objects in a zone occupying athree-dimensional space in the atmosphere above the Earth and forsimultaneously defending against the airborne objects located in thezone, comprising: a support for positioning adjacent the surface of theEarth at a bottom of the zone, the support having an outer extent with asubstantially convex outer surface, the outer extent of the supportcomprising a substantially hemispherical-shaped dome; detecting anddefending means mounted on the support for detecting airborne objects inthe zone and defending against the airborne objects in the zone, thedetecting and defending means comprising a plurality of clusters mountedon the support, each of the clusters transmitting along an axis defininga detection vector, the axis of the detection vector of each clusterextending into and through the zone, the axis of the detection vectorsof the plurality of the clusters radiating outwardly from the support ina substantially uniformly angularly separated manner, each of theclusters comprising: at least one radar assembly for detecting airborneobjects in the zone, the radar assembly comprising a radar transmitter,a radar receiver, and an antenna in communication with the radartransmitter and radar receiver, the radar transmitter transmitting alongthe axis of the detection vector, and the radar receiver receiving alongthe axis of the detection vector; at least one laser assembly fordefending against airborne objects in the zone, the laser assemblycomprising a laser transmitter for generating a coherent laser beam, thelaser assembly generating a laser beam oriented along an axis of adefending vector, the axis of the detection vector being substantiallyparallel to the axis of the defending vector; wherein the plurality ofclusters each have an outer limit of effective range that defines anouter periphery of the zone, the zone being substantially hemispherical;wherein each of the plurality of clusters includes a set of more thanone laser assembly, the set of laser transmitters of each cluster beingoriented such that the axis of the defending vector of each lasertransmitter of the set is substantially parallel to the axis of thedefending vector of other laser transmitters of the set; wherein thelaser transmitters of the laser assembly of each cluster are positionedaround the antenna of the radar assembly of the cluster; wherein theplurality of clusters are positioned in an array substantially coveringthe convex outer extent of the support; wherein the outer extent of thesupport comprises a surface, the surface of the support having aplurality supports formed therein for permitting passage therethrough ofcoherent laser beam of the laser assembly of the cluster and of radarsignals of the radar assembly of the same cluster such that radarsignals are selectively transmitted and received by the antenna of theradar assembly of the cluster; wherein the axis of the defending vectorof each of the clusters is oriented at an angle with respect to a normalaxis, the normal axis being oriented substantially perpendicular to aplane oriented tangent to the convex outer extent of the support, theaxis of the defending vector of each of the laser transmitters of theset of a said cluster being oriented at substantially the same anglewith respect to the normal axis, the angles formed by the axis of thedefending vector and the normal axis having a non-zero measurement;wherein the radar assembly of each cluster transmits and receives radarsignals at a frequency that is different from frequencies at which theradar assembly of each of the other clusters transmit and receive;wherein the laser transmitters are configured to generate laser beams ofvariable intensity, a range of intensities of the laser beams of thelaser transmitters ranging from a low intensity to a high intensity, thelow intensity being substantially harmless to airborne objects and thehigh intensity being configured to generate heat in an airborne object;wherein the intensity of the laser beams generated by the lasertransmitters have sufficient energy to destroy objects struck by thelaser beam within a predetermined distance from the laser transmitter inthe zone; wherein the laser transmitters are configured to selectivelygenerate laser beams having intensities greater than approximately 100kilowatts; wherein the intensity of the laser beams generated by thelaser transmitters is controlled by the controlling means, thecontrolling means increasing the intensity of the laser beams of thelaser transmitters as an airborne object moves closer to the support;controlling means for controlling the radar assemblies and the laserassemblies of the clusters, the controlling means comprising processingmeans for processing information from the radar transmitters and radarreceivers, the controlling means comprising storage means for storinginformation, the controlling means comprising identification means foridentifying authorized airborne objects in the zone, the identificationmeans comprising a radio receiver for receiving radio signals from anauthorized airborne object, the controlling means being configured tomodify operation of the clusters with respect to the authorized airborneobject when the radio signals are received from the authorized airborneobject until the authorized airborne object leaves the zone.